A conventional mobile device, such as a mobile telephone having a motion sensing system, typically allows an operator to input a command via a button. The button can be a stand-alone button, part of a keypad, part of a keyboard, or part of a touch screen. Actuating the button momentarily moves the mobile device by a slight amount. Accelerometers and gyroscopes in the mobile device's motion sensing system sense the momentary movement, which is not necessarily the motion intended to be detected by the mobile device's motion sensors. This momentary movement can alone seem insignificant, however, errors in sensed motion (e.g., acceleration and/or rotation rates) that each button actuation induces into the motion sensor output quickly accumulate. As a result, the cumulative effect of button actuation weakens the inertial sensing system's detection efficiency and lowers the system's accuracy.
Accordingly, there are long-felt industry needs for apparatus and methods that mitigate the shortcomings of conventional methods and apparatus, including improving motion sensing, mitigating an error in a motion sensor output, and accurately self-determining the mobile device's environment in the presence of a keystroke on the mobile device.